Diversity of Floricultural Insects and their impact on the Productivity of Cucurbita Maxima Dusch (Cucurbitaceae) in the Sudano-Sahelian Zone of Cameroon

Purpose: This study aims to assess the biodiversity of Cucurbita maxima pollinators with a view to optimising the expected results, in a context of efficient and sustainable agriculture in Cameroon. Methodology: In Vogzom (North), and in Torok (Far North) in 2022, Cucurbita maxima flowers (Cucurbitaceae) were observed in order to evaluate agronomic parameters, identify the floricultural entomofauna and the pollinating activity of Apidae. For the characterization of the floricultural entomofauna in Vogzom and Torok, five treatments of 30 female flowers each were established according to whether they were protected from visits by Apis mellifera (T0) or benefited from one visit (T2), two (T3), three visits (T4) each or were free (T1). A recognition code was assigned to each visiting species of Cucurbita maxima flowers and a few individuals of each species were captured and retained for later identification. The data collected was codified and encoded in the Excel spreadsheet of the Microsoft Office 2019 program. The normality test of the different variables was done by the Shapiro-Wilk test at the 5% significance level. The Tukey test was used for the comparison of means when the p-value was ˃ 5% and otherwise, the nonparametric Kruskal-Wallis test was used. Finding: The floricultural entomofauna associated with pumpkin consists of five species in Vogzom and fourteen species in Torok. Apidae (82.06%) were in the majority; represented by Apis mellifera (82.06%) in Vogzom. Similarly in Torok, Apidae (77.55%) were in the majority, represented by Apis mellifera with a relative abundance of 40.5%. The daily activity of the Apidae was effective between 6 a.m. and 1 p.m. with a morning peak of activity (6 a.m. to 7 a.m.) in both sites. Floral visits to collect nectar (74%) were more important than those devoted to pollen (26%) in A. mellifera. In Vogzom as well as in Torok. The fruiting and mature fruit rates as well as their average mass vary according to the number of successful insect visits by the female flowers. Contributions to theory, policy and practice: Overall, the fruit and seed production of Cucurbita maxima is closely dependent on the pollinating activity of the Apidae; without it, no fruit or seed is formed, as the pumpkin is neither parthenocarpic nor apomictic. Obtaining optimal pumpkin yields is conditioned by the conservation and protection of pollinator biodiversity.